LBS mechanics have two ways to do it:

A. 1/2 hour $35.00 tuneup way is to center the wheel in the stays WITHOUT checking dish - and align derailleur hanger against the wheel.

Pros = quick, dirty, and works...so long as that wheel stays there centered UNTOUCHED from there on out.

Cons = it's the wrong way to do it because while the hanger is aligned against the wheel - it may not be aligned in parallel with the frame. Also, non-linear loads may be applied to the axle lending to failure. Furthermore when an off-dish wheel is centered in the stays - it negatively impact bicycle handling - as two tracks are created instead of one resulting a tendency for the bike to "lean" to one side.



B. 1-2 hour tune-up in the $50.00 - $100.00 range.

Check dish of the wheel, center wheel in the the stays, align hanger parallel to the WHEEL AND TO THE FRAME

Pros = The right way to do it - anytime the wheel is replaced with a new wheel also properly dished - NO hanger alignment issues occur. An off dish wheel when installed will be self-apparent calling for correction. Also, when both front and rear wheels are properly dished - the wheels cannot be blamed for handling issue in the bicycle as a whole.

Cons = A lot more work as the wheel dishing consumes 10-15 minutes time, the hanger alignment another 5-10 minutes time.


More importantly, though, when you center a rear wheel that is OFF DISH - the freewheel / cassette is no longer operating in parallel with the frame. Depending upon the chain position - the chain will now unnecessarily hit the cog at an angle that introduces more wear than what typically would occur - this will be evident by a slight increase in noise.

The important thing to remember overall is that 99.99 percent of the bicycle frames we ride are built around a centerline. Everything on that frame operates on center with the frame centerline - or in parallel to it.

Rims, hubs, bottom brackets, headsets, seatposts, saddles and bars operate on the centerline. Cranksets, pedals, derailleurs, drum brakes, and disc rotors operate in parallel. Ensuring that they do so promotes the best operating efficiency for your bicycle whether it be handling, shifting, or chain wear.

=8-)